Rucete ✏ Biology In a Nutshell
1. Thermodynamics in Metabolism
- Exergonic Reactions: Release energy; characterized by a negative ΔG.
- Endergonic Reactions: Absorb energy; characterized by a positive ΔG.
2. Metabolism Overview
Metabolism consists of three main processes:
- Catabolism: Breakdown of substances.
- Anabolism: Synthesis of new products.
- Energy Transfer: Moving energy between molecules.
3. Chemical Equilibrium in Metabolism
- Metabolic reactions proceed towards chemical equilibrium.
- The direction of equilibrium depends on the concentration of reactants and products.
4. Enzymes in Metabolism
- Globular proteins that act as biological catalysts.
- Substrate Specificity: Each enzyme binds to a specific substrate.
- Reusability: Enzymes remain unchanged after reactions.
- Bidirectional Catalysis: Work for both forward and reverse reactions.
- Environmental Sensitivity: Activity is affected by temperature and pH.
- Naming: Most enzymes end in "-ase".
- Induced-Fit Model: Describes enzyme-substrate interaction
5. Cofactors & Coenzymes
- Cofactors: Non-protein molecules assisting enzymes.
- Coenzymes: Organic molecules.
- Inorganic Cofactors: Metal ions like Fe²⁺ and Mg²⁺.
6. ATP – Energy Currency
- ATP provides activation energy for metabolic reactions.
- ATP is converted into ADP (adenosine diphosphate) + Pi (inorganic phosphate) to release energy.
7. Enzyme Reaction Mechanisms
- Allosteric Enzymes: Have two binding sites – an active site (for substrate) and an allosteric site (for regulation).
- Competitive Inhibition: Inhibitor competes with substrate for the active site.
- Noncompetitive Inhibition: Inhibitor binds elsewhere, altering enzyme shape.
- Cooperativity: Binding of one substrate enhances enzyme affinity for more substrates.
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Biology in a nutshell